This invention relates generally to a control system and particularly to a sequential control system to compare external inputs with programmed conditions and then, if they are equal, to control load operations.
Various sequential control systems have been developed that employ memory means such as a random-access or a read-only memories. These systems may be classified into certain types from the aspect of soft-wares; that is, a type of programming according to a flow-chart, a type of programming by using logic algebra, and so on. However, some problems are encountered in the conventional control systems as follows: that is, they require considerable time for beginners to grow familiar with them, and furthermore require remarkable efforts for programming due to their complicated configurations.